698 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table I Effect of Method of Preparation upon the Properties of Triethanolamine Myristate/ Mineral Oil Emulsions Excess Myristic Acid System Range of Cream- Method of Temp Droplet ing Ag- Preparation Phase Composition a Order of of Diameters (/•) Time glomer- (No,) Aqueous Oil Mixing Mixing (hrs) ation • 1 H•O,TEA Oil, MA Aq. to oil RT 2-5 8-24 L 2 H20,TEA Oil, MA Aq. to oil 54.4øC 2-5 2-2.5 L 3 H20,TEA,MA Oil Aq. to oil RT 2-5 2-2.5 H 4 H•O,TEA,MA Oil Oil to aq. RT 2-10 1-1.5 H 50 . ..... 54.4øC 2-10 ... 6 H•O,TEA,MA 0ii Aq. tooil 54.4øC 2-15 0.•"1.0 H 7 All components mixed together 54.4øC 2-20 6-16 M 8 H•O,TEA Oil, MA Oil to aq. RT 2-20 1.5-2.0 M 9 H•O,TEA Oil,MA Oil to aq. 54.4øC 2-20 1.5-2.0 L 10 H•O,TEA, MA Oil Oilto aq. 54.4øC 2-20 0.5-1.0 H 11 H20 Oil,TEA,MA Oil to aq. RT 2-25 5-16 L 12 H, Oil,TEA,MA Aq. to oil 54.4øC % 2-25 3-16 L 13 H20 Oil,TEA,MA Aq. to oil RT 2-25 5-16 L 14 H20 Oil,TEA,MA Oilto aq. 54.4øC 2-35 3-16 L •TEA -- triethanolamine, MA = myristic acid. •L = low, M = medium, H -- high. •Prep. No. 5: MA heated to 54.4øC TEA, H, heated to 54.4øC aq. phase added to MA at 54.4øC mixture cooled to RT oil added at RT. This simulates the preparation of an aerosol. oil solution at 54.4øC. The poorest emulsion resulted when a mixture of min- eral oil, triethanolamine, and myristic acid at 54.4øC was added to water at 54.4øC. Possible reasons why these procedures produce the best and poorest emulsions are discussed later. Relationships Between Concentrates, Aerosol Emulsions, and Foa• General Properties The general properties of the aerosol emulsions and foams from the best and poorest concentrates are listed in Table IV. The data indicate that aerosol emulsions and foams from the best mineral oil concentrates are superior to those obtained from the worst concentrates. In aerosol emulsions with excess myristic acid, the superiority is shown by a slightly better stability to phase separation. There were no significant differences in the foam properties. In the excess triethanolamine system, the superiority of the emulsions and foams from the best concentrate is more evident. The aerosol emulsions have

AEROSOL EMULSIONS AND FOAMS 629 Table II Effect of Method of Preparation upon the Properties of Triethanolamine Myristate/ Mineral Oil Emulsions Excess Triethanolamine System Cream- Method o{ Temp Range of ing Ag- Preparation Phase Composition a Order of of Droplet Time g]omer- (No.) Aqueous Oil Mixing Mixing Diameters (/•) (rain) ation * 1 H20,TEA Oil, MA Aq. to oil RT • 2--40 30--60 L 2 H20,TEA Oil, MA Aq. to oil 54.4øC • 2-40 15-30 M 3 H,O,TEA Oil,MA Oil to aq. RT • 2--50 5-15 H 4 H•O,TEA Oil,MA Oilto aq. 54.4 øC • 2-60 5-15 M 5 H•O,TEA,MA Oil Aq..to oil RT • 2-60 • 5 H 6 H20,TEA,MA Oil Oilto aq. 54.4øC • 2-65 • 5 H 7 H,oO,TEA, MA Oil Oil to aq. RT • 2--70 • 5 H 8 H•O,TEA,MA Oil Aq. to oil 54.4øC 2--70 • 5 H 9 • • 2--70 • 5 H 10 All mixed together 54.4øC •2-95 • 5 H 11 H20 Oil,TEA,MA Oi! to aq. RT 5--95 • 5 M 12 H20 Oi],TEA,MA Aq. to oil 54.4øC 5-150 • 5 H 13 H_oO Oil,TEA,MA Aq. to oil RT 5-170 • 5 H 14 H20 Oil,TEA,MA Oilto aq. 54.4øC 15--190 • 5 H aTEA = triethanolamine, MA -- myristic acid. •L ---- low, M = medium, H -- high. CPrep. No. 9 MA heated to 54.4øC TEA,H_•O heated to 54.4øC aq. phase added to MA at 54.4øC mixture cooled to RT oil added at RT. This simulates the preparation of an aerosol, Table III Best and Poorest Methods for Preparing Aqueous Triethanolamine Myristate/Mineral Oil Emulsions and Their Properties -Method of Phase Preparation Composition • TEA/MA (No.) Aqueous Oil Ratio I H. Oil Excess (Best) TEA MA MA 14 H•O Oil Excess (Poorest) TEA MA MA I H,O Oil Excess (Best) TEA MA TEA 14 H, Oil Excess (Poorest) MA TEA TEA Order Temp of Droplet Cream- of Aqueous Size ing Agglom- Mixing Phase (a) Time eration Aq. to Room 2-5 8-24hr Low oil temp Oil to 54.4 øC 2-35 3-16 hr Low aq. Aq. to Room 2-40 30-60 High oil temp min Oil to 54.4øC 15-190 5min ttigh aq. aTEA: triethanolamine, MA = myristie acid,